For many years, it has been known to convey solid fluent materials such as grain, sand, etc. by means of auger-type conveyors. Such conveyors customarily comprise an elongated tube within which is mounted a helical blade connected at one end to a source of power which rotates the blade to displace the fluent material along the inside of the tube. While such conveyors have been entirely satisfactory in many different types of installations, they have certain limitations.
One of the primary disadvantages of conventional auger-type conveyors resides in the fact that in elevating solid fluent material, the conveyor must be inclined between the two different elevations. While an auger-type conveyor may be used to vertically lift solid fluent material to short distances, the tendency for such material to slide relative to the helical blades effectively prevents auger-type conveyors from being used to lift solid fluent material through substantial vertical distances. As a result, in order to lift such materials through substantial vertical heights, the auger-type of power conveyors customarily incline relative to the horizontal. Obviously, this has the disadvantage of requiring a greater length of conveyor for a given height of lift with a concomitant increase in cost and mounting problems.